the high-birth cohorts of the 1950's moved into childbearing. The under-5's would settle down at about 18 million.
The decline of births will have an effect on the number born in the next generation some 25 years later. As the smaller cohorts come into reproductive age, a further fall in the overall birth rate will take place, but it will be less extreme than the initial fall; the under-5's would still be 17.5 million by 1966. In the late 1980's the cohorts coming into the labor market would decline because of the original drop in births, and labor shortages might develop. Finally, the cohorts of the birth rate decline would reach the oldest ages about the middle of the 21st century when the number over 85 would drop from 4 million to about 3 million, about two thirds of whom would be women.
The social and economic effects of the changed birth rate would be different for the less developed country. For one thing, they would be more intense: the initial reduction in the youngest ages would be greater, though the ultimate population would be much higher above the initial one. Mortality would continue to improve (which it is by no means sure to do in the United States), and this would make the ultimate population greater than that calculated by a constant death rate, so that the 50 to 67 percent increase that we find after the stationary birth regime is adopted seems conservative. Among the consequences of the sudden drop in fertility would be a smaller number of babies; although the most immediate effect, it would not be the most fundamental. With fewer babies the national income per capita would be higher than if the high birth rates had continued, but this improvement is of a formal character, since the consumption of the babies is not great and their production is zero.
The economic improvement would be more real to the public and to administrators when the smaller cohorts reached school age. With fewer entrants the amount of teaching personnel and facilities devoted to each child could be greater. A larger proportion of the new smaller cohorts could attend school and receive better instruction than would otherwise be possible. In some countries today increasing school budgets are accompanied by smaller fractions of the new cohorts attending school.*
The most important effects of the drop in the birth rate would be seen some 20 years later when entrants into the labor force would decline. Each of the new entrants would have greatly improved possibilities of effective employment, given the sharply limited capital. Members of the smaller cohorts will be able to work with more capital than would have been accessible to them if they were more numerous, and this means more and better jobs. A further possible advantage of their smaller numbers is a larger ratio of managers to workers if management is provided by those older than
*Sec Gavin W. Jones, "Effect of Population Change on the Attainment of Educa-bout 20 percent. For the less developedHilton Salhanick has observed that some women practicing the rhythm method will break or lose their thermometers at the critical juncture in theirright, therefore alwayshas some c